Patients Referred to an Allergist or Immunologist Following an Anaphylactic Event Have Better Outcomes

New research provides some of the first concrete support for a treatment guideline that has long been recommended on grounds of common sense alone: Patients who suffer severe allergic reactions such as anaphylaxis should follow up on their emergency room care by seeing an allergist or immunologist.

The authors of the study, which was printed in The Journal of Allergy and Clinical Immunology: In Practice, reviewed the records of 573 patients who sought emergency room treatment for anaphylaxis.

Emergency room doctors recommended that all of the patients schedule an appointment with a specialist, but only 217 of the patients (38%) complied with that advice and went on to see an allergist or immunologist.

Among that group, subsequent testing significantly altered the initial diagnosis and, therefore, the recommended lifestyle modifications for 77 of them (35%; 95% confidence interval [CI], 29%-42%).

In 16 of those cases (7%; 95% CI, 5% - 12%), the specialists determined that the patients had never undergone anaphylaxis at all and that emergency room doctors had fundamentally misidentified the problem.

Specialists also managed to identify triggers for 24 of the 74 patients who had no idea what sent them to the emergency room (32%; 95% CI, 23% - 44%), to correct mistaken conclusions among 9 of the 143 patients who thought they knew what triggered their attacks (6%; 95% CI, 3% - 12%) and to identify a mast cell activation disorder in 4 patients (2%; 95% CI, 0.7%-4.6%).

For 13 of the patients who went on to see allergists and immunologists, those consultations eventually led to immunotherapy designed to prevent future episodes of anaphylaxis.

“These results underscore the importance of allergy/immunology follow-up after an ED visit for anaphylaxis,” wrote the authors of the study, a retrospective review and analysis of patient records from April 2008 to August 2012.

The study team supports this assertion on grounds that more accurate diagnoses should help patients in their efforts to avoid triggering subsequent attacks and that immunotherapy should confer some resistance in case of subsequent exposure.

That said, the researchers did not compare those patients who sought follow-up care to those patients who did not and check whether the former group went on to suffer fewer additional cases of anaphylaxis than the latter group.

Worse, according to one recent meta-study undertaken to create new anaphylaxis-care guidelines for the European Academy of Allergy and Clinical Immunology (EAACI), no study has compared the outcomes of patients who do and do not receive treatment from specialists after their initial allergic reactions.

The EAACI’s review gave a “C” grade to the recommendation that each person who goes to the emergency room with anaphylaxis should work with doctors to develop an anaphylaxis management plan designed to prevent additional reactions and manage any that occur.

The authors of the new study believe their work, despite being a retrospective analysis rather than a controlled trial, adds significant evidence in support of expert follow-up. Patients cannot avoid triggers, the researchers argue, if they don’t know what triggers their attacks.

The taskforce behind the new EAACI recommendations, on the other hand, sees little value in more small studies that mine existing data. Its members argued earlier this year that large randomized trials offer the only hope of bringing any real certainty to anaphylaxis care.